protected void appendJarFile(final String cpSeparator, final StringBuilder buf, final File libDir, final String basePath) {
        final File[] jarFiles = libDir.listFiles((FilenameFilter) (dir, name) -> name.toLowerCase().endsWith(".jar"));
        if (jarFiles != null) {
            for (final File file : jarFiles) {
                buf.append(cpSeparator);
                buf.append(basePath);
                buf.append(file.getName());

            final List<Artifact> list = new ArrayList<>(jarFiles.length);
            for (final File file : jarFiles) {
                list.add(getArtifactFromFileName(artifactType, file.getName()));
            }
            list.sort(Comparator.comparing(Artifact::getName));
            return list.toArray(new Artifact[list.size()]);
        }

        final File[] jarFiles = ResourceUtil.getPluginJarFiles(artifactType.getId());